We know that Pottersville, or P is 51 miles south of Dubuque, or D, and that Westview (W) is 60 miles west of Dubuque. I want to look at this more visually, so let's set it up:
color(white)(......)60 miles
W-----------D
color(white)(.)\color(white)(...........)|
color(white)(.)color(white)(.)\color(white)(.........0)|
color(white)(.)color(white)(..)\color(white)(.........)|color(white)(.)51 miles
color(white)(.)color(white)(30.)\color(white)(0000)|
color(white)(.)color(white)(0330)\color(white)(333)|
color(white)(.)color(white)(00000)\color(white)(33)|
color(white)(.)color(white)(0000..)\color(white)(3)|
color(white)(.)color(white)(3333333)P
By drawing the problem, we can see that this is a triangle. Now we can use Pythagoras formula, which is a^2+b^2=c^2.
This means that 60^2+51^2=c^2, or 6201=c^2. The sqrt(6201)=78.746, which we'll round up to 78.75. That means that the distance from Pottersville to Westview is 78.75 miles.
